The present invention relates generally to a medical device which reduces the appearance of scars and stretch marks using infrared heating and ultraviolet light.
Stretch marks are a common skin condition and are essentially linear dermal scars accompanied by epidermal atrophy. They are caused by stretching the skin. This skin distension leads to excessive mast cell degranulation with subsequent damage of collagen and elastin. They can affect almost 90% of pregnant women, 70% of adolescents, and 40% of males. The most common sites to be affected by stretch marks include the breasts, buttocks, thighs and lateral abdomen. The appendages normally present in skin—including hair follicles, sweat glands and other structures are absent in areas affected by stretch marks.
As previously mentioned, stretch marks are a form of scarring that takes place in the skin as a result of dermal tearing secondary to stretching. Degranulation of dermal mast cells imparts damage to the elastin and collagen fibrils in the dermis causing them to fracture. This results in thinning of the dermal layer. This loss of structural integrity causes the overlying epidermis to atrophy. Stretching of the skin is not the sole cause. Genetic factors altering collagen ratios in the skin and glucocorticoids produced in the body or taken medically can also contribute. Stretch marks are less likely to form with adequate dermal sub-structure. They are more likely in people with a high body mass index (BMI), low maternal age, weight gain if greater than about 15 kg., or people with a higher than normal neonatal birth weight.
Stretch marks appear initially as reddish or purplish lines in the skin with palpable contour irregularities. Just like other scars, they acutely initiate the inflammatory reaction needed to heal with subsequent vascular dilatation in the wound area giving the reddened or purplish color. Localized swelling may initially give the stretch mark a raised contour which subsides as the edema fades. Although permanent, they mature over time as the vascular dilatation resolves and scar remodeling takes place leaving a less noticeable but permanent defect.
Since damaged collagen fibrils are at the center of the problem, it is beneficial to understand collagen in order to help repair it. Collagen is a subunit of larger aggregates called fibrils. It is typically about 300 nm in length and 1.5 nm in width. It is comprised of 3 polypeptide chains called alpha chains. They are “left handed” helices twisted together to form a “right Handed” coil called a triple helix. These helices are stabilized by hydrogen bonding. They contain a regular arrangement of amino acids. The fibrils are semi crystalline aggregates of collagen molecules bundled together called fibers. These fibers are arranged in different combinations and concentrations in various tissues to provide the various tissue qualities. Skin is made up of mostly type I and type III collagen, Type III being mostly reticular fibers.
Treatment is aimed at repairing the damaged collagen fibrils and diminishing aesthetic impact with early treatment being optimal. Various treatments are available for the purpose of improving the appearance of existing stretch marks, including laser treatments, dermabrasion, and prescription retinoids. In addition, the use of a pulsed dye laser has been shown to increase pigmentation in darker skinned individuals with repeated treatments. However, if the epidermis and the dermis has been penetrated, laser will not remove the stretch marks.
A surgical procedure for removing lower abdominal stretch marks is the tummy tuck, which removes the skin below the navel where stretch marks frequently occur. A new modality, fractional laser resurfacing, offers a novel approach to treating striae. Using scattered pulses of light only a fraction of the scar is zapped by the laser over the course of several treatments. This creates microscopic wounds. The body responds to each treatment by producing new collagen and epithelium.
While each of these procedures provide varying levels of success in the removal, or reduced appearance, of stretch marks, all of these procedures are performed using very expensive equipment in a physician's office. Accordingly, a need exists for a portable, simple to use device which will allow for the removal of stretch marks from the skin.